Generally, stuff resolves in a First in First out method. The rule book mentions Nested Actions which resolve in a Last in First out method.

Can someone give me a few examples, going as deep as possible with actual existing cards, of when the Last in First out method would be used?

Cancels of cancels Id think. Nullify your nullify. The last one in is the one that actually succeeds in its effect

Nullify the Nullify and also Reactions to commitment in the case of Ragnar and Forsight for example. This latter also has to do with which player has the initiative.

'Last In First Out' or LIFO should only be used when a new trigger opportunity arises. Interrupts are the best example, as you might Interrupt an Interrupt (as the Nullify vs Nullify example above).

For example, let's look at Ragnar's Hunt vs Foresight, with their respective Warlords (everything here triggers on the same timing event; committing to a planet).

We'll look at how it works with different players having initiative. I chose this example because I already wrote it at CardGameDB.com, which is me being lazy but hopefully, it'll help with the understanding of nested effects.

We assume that Ragnar deploys to a planet adjacent to the one Eldorath deploys to.

Ragnar has initiative:

Interrupt window

Warlords Commit

Reaction window (Ragnar Trigger's the Hunt)

Interrupt window

Ragnar Re-commits

Reaction window (Ragnar triggers himself, doing 2 damage)

Interrupt window

Eldorath re-commits

Reaction window

Eldorath has Initiative:

Interrupt window

Warlords Commit

Reaction window (Eldorath passes, as he is on a different planet to Ragnar; Ragnar triggers the Hunt)

Interrupt window

Ragnar Re-commits to Eldorath's planet

Reaction window (Ragnar triggers himself, doing 2 damage)

Interrupt window

Eldorath re-commits

Reaction window

Eldorath gets face-punched again! Not looking good! One last chance -

Eldorath has initiative:

Interrupt window

Warlords Commit

Reaction window (Eldorath, fearing Ragnar's Hunt, triggers Foresight)

Interrupt window

Eldorath re-commits, at least 2 planets away from Ragnar, denying him the opportunity to face-punch Eldorath

Reaction window

So for Eldorath to escape unharmed, you must have Initiative, Foresight (the card) and foresight enough to suspect Ragnar coming for your blood!

Now, if we feel like complicating matters further, let's add in some shielding and No Mercy!

Ragnar has initiative:

Interrupt window

Warlords Commit

Reaction window (Ragnar Triggers the Hunt)

Interrupt window

Ragnar Re-commits

Reaction window (Ragnar triggers himself, doing 2 damage)

Damage is assigned to Eldorath (note there is a window before and after this for interrupts and reactions to damage being assigned, but we'll ignore that for now)

Eldorath discards a 2-shield card to ignore the damage

Ragnar plays No Mercy and exhausts himself to interrupt and cancel the shielding

Eldorath plays Nullify to cancel the No Mercy (exhausting himself)

No Mercy is cancelled

Because No Mercy was cancelled, the damage from Ragnar is shielded

Interrupt window

Eldorath re-commits

Reaction window

-snip- figuring out how to delete this.

Probably the most important thing to recognize in this discussion is that all effects in the same window resolve "first in, first out." But if an effect in window A opens up sub-window B (and effects in sub-window B open up sub-window C, etc.), then the newly created windows are resolved "last in, first out."

So, what I'm getting from this, is LIFO only applies when there are interrupts or shields being used, is that right?

Edit: Although, I suppose an interrupt resolving in front of some other ability could cause something else to trigger that needs to be resolved be for the first in ability resolves...

I think I get it.

So, what I'm getting from this, is LIFO only applies when there are interrupts or shields being used, is that right?

Edit: Although, I suppose an interrupt resolving in front of some other ability could cause something else to trigger that needs to be resolved be for the first in ability resolves...

I think I get it.

Yeah, you seem to be on the right track. It's not just Interrupts and Shields though.

Let's say both players have a reaction to the same event (continuing the above example, that's Warlords committing).

Both players resolve their reactions, one at a time, to the commitment. These go FIFO (First In, First Out).

However, if any of those reactions can THEMSELVES be reacted to (or interrupted) we get nesting. Those nested effects will resolve BEFORE we continue to resolve the original reactions to the Commitment.

So let's say we have a commitment with 3 effects that will trigger from 'when you commit'. We'll call them A B and C.

Commitment

Reaction A

Reaction B

Reaction C

However, Reactions B and C trigger some other reactions. We'll call them B1/2 and C1/2.

So now we get

Commitment

Reaction A

Reaction B

Reaction B1

Reaction B2

Reaction C

Reaction C1

Reaction C2

Even though C is reacting to the original trigger (the commitment) B1 and B2 will still resolve before C because of the nesting effects.

Hope that makes sense, and doesn't further confuse things.

While I see what you are saying, that newly triggered abilities get to trigger and resolve before we can go back to the original reaction window and trigger more abilities, the latter haven't triggered yet so I don't consider them 'In', so to speak. Does that make sense?

I was mostly wondering when you'd ever have multiple abilities triggered already but not resolved. It seems that requires an interrupt to happen.

I'm sorry, I don't really understand what you mean now. In the example I just gave, you have got three effects (A B and C) which are all triggered but not yet resolved. When you get into the first sequence of nested effects you now have additional abilities which are triggered but not resolved (B1, B2, C).

If B1 and B2 were interrupts instead all it does is change the order slightly to

Reaction A

Interrupt B1

Interrupt B2

Reaction B

Reaction C

Reaction C1

Reaction C2

I was mostly wondering when you'd ever have multiple abilities triggered already but not resolved. It seems that requires an interrupt to happen.

I'm sorry, I don't really understand what you mean now.

I think what he's getting at is that since Reaction C hasn't even been triggered yet while you are resolving Reaction B (and B1 and B2 in the sub window for reactions specifically to Reaction B), how can Reaction C be considered part of a "first in, first out" stack in the first place?

@alpha: The nature of FIFO is that it really doesn't create conventional effect "stacks" at all because, as you rightly say, the previous effect has to resolve entirely before the next one can trigger in the first place. It's better to think of the FIFO timing of this game as defining when things can be triggered relative to other effects, not when they resolve relative to other active effects.

You are correct that Interrupts are the only effects in this game that can resolve between the triggering and resolution of other effects (including other interrupts). In that sense, the only time you will see conventional effect "stacks" in this game is when interrupts are involved.

The "nesting" of reactions (when reactions create new triggering conditions; what we have mainly been talking about in this thread) is similar, but because they don't break the "initiate-resolve" chain of any active, triggered effects, the nested windows are not really the same as stacked effects as other CCGs and TCGs define them.

Awesome, this helps my understanding a ton.